• Basic Info
• Top Questions
• Clinical Info
• Interactions

Before taking azathioprine, tell your doctor if you are taking, have taken, or need to take any of the following medicines:

• allopurinol (Zyloprim);

• mercaptopurine (Purinethol);

• methotrexate (Rheumatrex, Immunex);

• a blood thinner such as warfarin (Coumadin);

• cyclosporine (Neoral, Sandimmune);

• olsalazine (Dipentum), or sulfasalazine (Azulfidine);

• sulfamethoxasole and trimethoprim (Trimpex, Proloprim, Bactrim, Septra, others); or

• an ACE inhibitor such as benazepril (Lotensin), captopril (Capoten), fosinopril (Monopril), enalapril (Vasotec), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), ramipril (Altace), or trandolapril (Mavik).

This list is not complete and there may be other drugs that can interact with azathioprine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

• pale skin, easy bruising or bleeding, unusual weakness;

• fever, chills, sore throat, body aches, weakness, muscle pain, flu symptoms;

• severe nausea, vomiting, or diarrhea;

• severe pain in your upper stomach spreading to your back, fast heart rate;

• pain or burning with urination;

• stomach pain, loss of appetite, dark urine, clay-colored stools, and jaundice (yellowing of the skin or eyes); or

• white patches or sores inside your mouth or on your lips.

Less serious side effects may include:

• mild upset stomach, nausea, diarrhea, loss of appetite;

• hair loss; or

• skin rash.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.